```js
// MyComponent.stories.js

import MyComponent from './MyComponent.svelte';

export default {
  component: MyComponent,
  title: 'A story using environment variables inside a .env file',
};

const Template = (args) => ({
  Component: MyComponent,
  props: args,
});

export const Default = Template.bind({});

Default.args = {
  propertyA: process.env.STORYBOOK_DATA_KEY,
};
```